January 19, 2018:

Adaptive Cuckoo Filters

Timothy Johnson

We introduce the adaptive cuckoo filter (ACF), a data
structure for approximate set membership that extends cuckoo filters
by reacting to false positives, removing them for future queries. As
an example application, in packet processing queries may correspond to
flow identifiers, so a search for an element is likely to be followed
by repeated searches for that element. Removing false positives can
therefore significantly lower the false positive rate. The ACF, like
the cuckoo filter, uses a cuckoo hash table to store fingerprints. We
allow fingerprint entries to be changed in response to a false
positive in a manner designed to minimize the effect on the
performance of the filter. We show that the ACF is able to
significantly reduce the false positive rate by presenting both a
theoretical model for the false positive rate and simulations using
both synthetic data sets and real packet traces.